An exemplary application, according to the present invention, aims to provide an emergency light including a light source having excellent electric power efficiency and long operating life, a wireless emergency light data transmission system that uses the emergency light as a data transmission source while in an emergency, and an emergency light that is used in the system.
To attain this objective, an emergency light, which is embedded with a battery and turns a light source on while in an emergency without electric power supplied from an external power source, is characterized by the light source made up of LEDs. The feature of LEDs or high electric power efficiency allows suppression of battery consumption. Reduced battery size allows reduction in device size. Moreover, extended operating life as to light emitting time is provided. Moreover, since LEDs have a long operating life, intervals between maintenance such as light source replacement intervals can be extended, which allows reduction in maintenance cost. Furthermore, since LEDs are highly crash proof, an available emergency light that will not be damaged due to a devastating disaster can be provided.
The emergency light further includes a storage unit that is stored with data to be transmitted while in an emergency and an optical modulator that controls electric power supplied to the LEDs in accordance with data stored in the storage unit, so as for the LEDs to change light intensity or blink. As described above, since LEDs have an excellent response speed characteristic, modulation based on such data is possible, and light for displaying can be used for data transmission as is. With such structure, the emergency light, which is conventionally used merely for indicating an emergency exit and an emergency staircase, can be used as a data source while in an emergency. At this time, since the light source, which functions as an emergency light, is used as is, it never consumes large electric power as opposed to the case of voice output. As a result, most of electric power consumption is expected to be an amount for only the light source. As a result, there is no need to provide an additional large-capacity battery for transmitting data, thereby allowing the light source to operate as a data source with a battery provided for display.
Alternatively, a demodulator may be provided, so as to separate data, which is superimposed on a voltage of an external power source and then transmitted, while being driven by an external power source while not at a time other than in an emergency. Data provided from the modulator is then stored in a storage unit. Such a structure allows distribution of data, which is to be transmitted while in an emergency, to respective emergency lights via the power line while not in an emergency. As a result, data to be transmitted while in an emergency can be easily set and updated.
According to the present invention, a wireless emergency light data transmission system for transmitting data to a terminal using an emergency light, which has a light source turned on while in an emergency without electric power supplied from an external power source, is provided. In the wireless emergency light data transmission system, the emergency light includes a battery, an LED that is used as a light source, a storage unit that is stored with data to be transmitted while in an emergency, and an optical modulator that controls electric power supplied to the LED in accordance with data stored in the storage unit, thereby controlling light intensity or blinking of the LED. The terminal includes a light receiving unit that receives light emitted from the LED in the emergency light and converts it to an electric signal, and a demodulator that demodulates the electric signal output from the light receiving unit, thereby capturing the data. This structure allows optical data transmission from an emergency light to a terminal while in an emergency. Various pieces of data such as escape routes for evacuees, informing destination, or a map and descriptive text data for floors can be displayed on the terminal, which allows smoothly guiding users to evacuate while in an emergency.